Unsaturated hydrocarbons polymerization catalysts containing transition metal complexes and Bronsted acids

ABSTRACT

Catalysts compositions and methods for polymerizing conjugated diolefins comprising 
     (a) A complex of a transition metal of Groups IV through VIII of Mendeleev&#39;s Periodic Table as a nuclear atom and unsaturated hydrocarbon having at least one pair of π electrons as ligand, and 
     (b) A Bronsted acid. 
     Preferred embodiments include a catalyst resulting from a pre-treatment of (a) with a conjugated diolefin and the polymerization process incorporating the pretreated catalyst.

This invention relates to a novel catalytic composition which issuitable for the polymerization of unsaturated polymerizable compoundsinto stereoregular high molecular weight polymers having, for example,an intrinsic viscosity, as measured in benzene at 30° C., higher than0.1. These catalysts are particularly applicable to the production of1,4-stereoregular polymers of conjugated diolefins.

In the periodical "Angewandt Chemie" 73 (1961), page 33, Wilke hasindicated that complexes of transition metals with organic ligands doselectively catalyze the conversion of unsaturated compounds intooligomers. It has also been found that it is sometimes possible toobtain high molecular weight polymers of low stereoregularity if suchcomplexes were employed while utilizing very severe reaction conditions,such as high temperatures and exceptionally long reaction times. In viewof such knowledge, it appeared that the utilization of complexes ascatalysts was of no practical significance for the polymerization ofconjugated diolefins. However, the basis of the present invention is thediscovery that such complexes, when employed with a second component,result in catalysts which are indeed very promising.

An object of this invention, therefore, is to provide novel catalyticcompositions comprising complexes of transition metals with organicligands.

Another object is to provide polymerization processes for the productionof conjugated diolefins, said processes being based on the novelcatalytic compositions of this invention.

Upon further study of the specification and claims, other objects andadvantages of the present invention will become apparent.

To attain the objectives of this invention, there is provided a catalystcomposition comprising:

(A) A complex of an unsaturated hydrocarbon and a transition metal ofGroups IV to VIII (Subgroups A and B) of Mendeleev's Periodic Table; and

(B) A compound having the properties of a Bronsted acid (a proton donor,see Pauling "Chimie Generale," Dunod (1958), page 455).

This novel catalytic composition thus contains, a cocatalyst (b) whichis inexpensive, readily available, and easy to use.

According to this invention, the complex of the transition metal is tobe understood as a complex containing in general 1-4, preferably 1-2ligands. These ligands are preferably unsaturated hydrocarbons whichcontain at least one pair of π-electrons, for example, mono- anddi-ethylenically unsaturated hydrocarbons, aromatic hydrocarbons, andallyl hydrocarbons. Such hydrocarbon ligands can be employed with orwithout other ligands which can contain carbon oxides or quinones. Thesecomplexes are also considered to be coordination compounds, see"International Encyclopedia of Chemical Science," Van Nostrand (1964),pp. 602-606.

The preferred group of ligands consists of cyclopolyolefins, principallythose controlling 5.18 carbon atoms per molecule and having a nucleus of5-14 carbon atoms. Such cyclopolyolefins contain 2-6, preferably 2-4double bonds per molecule. Catalysts composed of these ligands are bothhighly active and particularly selective.

Among the complexes of transition metals which can be employed in thisinvention, the most preferred is bis-(1,5-cyclooctadiene) nickel;however, the following complexes also yield excellent results:

bis-(cyclopentadiene) nickel

bis-(cyclopentadiene) cobalt

cyclooctateraene nickel

1,5,9-centro (trans, trans, trans cyclododecatriene) complexes

dibenzene chromium

bis-(π-allyl) nickel

π-allyl-cyclopentadienyl nickel

tris-(π-allyl) chromium

tris(trans-stilbene) nickel

bis-(hexamethyl-benzene) chromium

dibenzene vanadium

dibenzene molybdenum

cyclopentadiene benzene molybdenum

1,3-cyclohexadiene, cyclopentadiene palladium

1,3-cyclohexadiene, benzene ruthenium

cyclohexadiene nickel

bis-(3,7-dimethyl-1,5-cyclooctadiene) nickel

bis-(3-phenyl-1,5-cyclooctadiene) nickel

Still further examples of usable complexes are:

1,5-cyclooctadiene-duroquinone nickel

cyclooctatetraene-duroquinone nickel

cyclopentadiene vanadium tetracarbonyl

benzene molybdenum tricarbonyl

cyclopentadienyl dicarbonyl cobalt

cycloheptatriene tricarbonyl chromium

1,5-cyclooctadiene tetracarbonyl chromium

dicyclohexadiene-1,3-dicarbonyl molybdenum

5,6-dimethylene bicyclo-2,2,1-heptene-2-tricarbonyl molybdenum

These various complexes are generally soluble in hydrocarbons in aproportion of at least 0.01% by weight.

As specific examples of the compounds exhibiting Bronsted acidproperties, there are included:

Mineral acids, such as hydrofluoric acid, hydrochloric acid, sulfuricacid, peroxy(mono)sulfuric acid, nitric acid, phosphoric acid, hydriodicacid, and hydrobromic acid.

Organic acids, such as acetic acid, formic acid, isobutyric acid,monochloroacetic acid, dichloroacetic acid, trichloroacetic acid,trifluoroacetic acid, as well as other carboxylic acids in general, andfurthermore benzenesulfonic acid, paratoluenesulfonic acid,α-napthalenesulfonic acid, as well as other sulfonic acids, and stillfurther picric acid and sulfinic acids, etc.

For further specific examples, reference is directed to tables of acidswhich are listed in "Handbook of Chemistry and Physics," latest edition,Lang's "Handbook of Chemistry," latest edition, Kirk-Othmer"Encyclopedia of Chemical Technology," Second Edition, vol. 1, pp. 226,229-231-232, 234-235-236, 238-239-240 in particular. The disclosure ofacids in such reference works is to be considered as incorporated inthis disclosure.

Of the Bronsted acids, it is preferred to employ strong acids whichexhibit a dissociation constant of higher than 10⁻⁴ at 25° C. With suchacids, the resultant catalyst substantially increases the reactionvelocity of the polymerization.

The ratio of compound (a) to compound (b) can vary greatly; for example,it is possible to utilize 0.01-50 mols of compound (a) to 1 mol ofcompound (b). Though all of these ratios will result in a finitecatalytic activity, it is to be emphasized that certain ratios givebetter results than others. For example, to obtain a high degree ofconversion of the monomer to a polymer having a high molecular weightand stereoregularity, as well as being soluble in hydrocarbons, it ispreferred to employ a ratio of 0.1-3 mols of compound (a) to 1 mol ofcompound (b).

Particularly preferred combinations of (a) and (b) are as follows:

    ______________________________________                                        Combination No.                                                                           Complex (a)  Acid (b)                                             ______________________________________                                        (1)         (C.sub.5 H.sub.5).sub.2 Ni                                                                 HCl                                                  (2)         (C.sub.5 H.sub.5).sub.2 Ni                                                                 CF.sub.3 COOH                                        (3)         (C.sub.8 H.sub.12).sub.2 Ni                                                                HCl                                                  (4)         (C.sub.8 H.sub.12).sub.2 Ni                                                                HBr                                                  (5)         (C.sub.8 H.sub.12).sub.2 Ni                                                                HI                                                   (6)         (C.sub.8 H.sub.12).sub.2 Ni                                                                H.sub.2 S.sub.2 O.sub.7                              (7)         (C.sub.8 H.sub.12).sub.2 Ni                                                                CCl.sub.3 COOH                                       (8)         (C.sub.8 H.sub.12).sub.2 Ni                                                                CF.sub.3 COOH                                        (9)         (C.sub.8 H.sub.12).sub.2 Ni                                                                CH.sub.3 SO.sub.3 H                                  (10)        (C.sub.8 H.sub.12).sub.2 Ni                                                                CH.sub.3 C.sub.6 H.sub.4 SO.sub.3 H                  (11)        (C.sub.8 H.sub.12).sub.2 Ni                                                                (NO.sub.2).sub.3 C.sub.8 H.sub.2 OH                  (12)        (C.sub.8 H.sub.12).sub.2 Ni                                                                CCl.sub.3 COOH/SnCl.sub.4                            (13)        (C.sub.8 H.sub.8)Ni                                                                        HCl                                                  (14)        (C.sub.8 H.sub.6)Ni                                                                        CF.sub.3 COOH                                        (15)        (C.sub.6 H.sub.8).sub.2 Ni                                                                 HCl                                                  (16)        (C.sub.6 H.sub.8).sub.2 Ni                                                                 CF.sub.3 COOH                                        (17)        (C.sub.12 H.sub.18)Ni                                                                      HCl                                                  (18)        (C.sub.12 H.sub.18)Ni                                                                      HBr                                                  (19)        (C.sub.12 H.sub.18)Ni                                                                      CF.sub.3 COOH                                        (20)        (C.sub.12 H.sub.18)Ni                                                                      CCl.sub.3 ClOH                                       (21)        (C.sub.12 H.sub.18 )Ni                                                                     (NO.sub.2).sub.3 C.sub.6 H.sub.2 OH                  (22)        (C.sub.12 H.sub.18)Ni                                                                      CCl.sub.3 COOH/SnCl.sub.4                            ______________________________________                                    

The activity of the catalysts can be increased even further by addingother components which are capable of forming a complex with the acidwhile increasing its acidity. Such additives are metal halides, forexample, BF₃, SnCl₄, SbCl₅.

The amount of catalyst that is employed for the polymerization.[.reation.]. .Iadd.reaction .Iaddend.is dependent on the desiredreaction velocity and also the molecular weight of the final polymer. Asin other polymerization reactions, the higher the content of thecatalyst, the more rapid the polymerization, but the lower the molecularweight of the polymer. Consequently, a catalytic quantity of thecatalyst is added which is dependent upon the desired results. Ingeneral, there are employed at least 0.001 atoms of metal (in the formof the complex), preferably 0.1-2 atoms of metal per 100 mols ofmonomer. The latter preferred proportions lead to polymers having themaximum stereoregularity.

The polymerization reaction is conducted with or without a solvent, at atemperature generally between -40° and +120° C., preferably a range ofabout 20-75° C. which leads to polymers of excellent stereoregularity.

As for the pressure to be employed for the polymerization reaction, theonly criterion is that a pressure must be selected so that the monomeris in the liquid phase at the polymerization that is employed, thehigher the pressure that is necessary.

As for the addition of compounds (a) and (b), it is preferred to mixthem only in the presence of the monomer in order to avoid sidereactions. In this connection, a preferred embodiment of this inventionembraces the utilization of a pretreatment for compound (a) of thecatalyst before it is mixed with compound (b).

The pretreatment comprises mixing component (a) with some monomer,preferably in the presence of an inert solvent, such as a paraffinic oraromatic hydrocarbon. It is advantageous, in this connection, to use atleast 0.5 mol of monomer, more preferably 3-30 mols of monomer, permetal atom in the form of the complex. Component (a) is maintained incontact with a monomer at a convenient temperature, for example, between-20 and +100° C., preferably between 0 and 60° C. for a residence timegenerally higher than 1 minute, for example, 10 minutes to 24 hours.During the course of this contact, or preferably following same, it isadvantageous to evaporate at least a part of the hydrocarbon which wasinitially present in the form of the complex. During this evaporation,uncombined monomer, as well as any solvent initially present can also beremoved in whole or in part. The resultant undistilled productconstitutes pretreated component (a) of the catalyst.

Catalysts comprising pretreated component (a) and component (b) aregenerally more active than the same catalysts which are based onunpretreated component (a).

The most preferred method for conducting polymerization comprisesreacting the pretreated component (a) with the Bronsted acid in theabsence of monomer. Following this reaction, unreacted excess acid isremoved, for example by evaporation and distillation; and this productis then added to the monomer which is to be polymerized. By thistreatment, the excess free acid is advantageously eliminated, therebyavoiding side reactions during polymerization, and also reducing thecorrosiveness of the reaction milieu, which can result in considerablesavings with respect to the selection of materials of construction.

The novel catalyst composition of this invention is useful for thepolymerization of generally all unsaturated polymerizable compounds andmixtures thereof. It has been found, moreover, that the catalystcomposition is particularly applicable to the polymerization ofethylenically unsaturated hydrocarbons containing up to 20 carbon atoms,for example, isoprene and styrene. Excellent results are obtained whenthe monomer is a conjugated diolefin containing 4-7 carbon atoms,particularly butadiene.

The catalyst composition is also good for the polymerization ofmono-olefins to yield high molecular weight polymers, particularly fromethylene.

As solvents for the polymerization reaction, it is advantageous toselect inert hydrocarbons, in particular, aromatic, paraffinic, orcycloparaffinic hydrocarbons, or their halogenated derivatives,particularly the chlorinated derivatives. When non-polar hydrocarbonsare employed as solvents, the polymerization reaction is stereospecificto the cis-1,4-form whereas polar solvents lead to the formation of thetrans-1,4-form.

Particularly preferred solvents for this invention are pentane, hexane,heptane, octane, isoheptane, isooctane, benzene, toluene, xylene,cyclohexane, and methylcyclohexane.

If, as component (a), a complex is selected which is decomposed bywater, it is then preferred to operate in an anhydrous reaction medium,or one which contains only slight traces of water.

Aside from the previously mentioned catalytic components, it is alsopossible to add various polymerization additives which are compatiblewith components (a) and (b), which additives are conventionally employedregulators, for example.

The polymerization reaction can be conducted under autogenous pressureor under any total pressure sufficient to maintain the reaction mixturesubstantially in the liquid phase. The pressure is a function of boththe particular diluent employed, and also the polymerizationtemperature. If highly elevated pressures are employed, any appropriatetechnique can be used, such as the utilization of a high pressure gaswhich is inert under the conditions of the polymerization reaction.

Any conventional technique can be employed for conducting thepolymerization reaction, such as a continuous polymerization,semicontinuous polymerization in serially connected polymerizationreactors, or entirely in one batch in a reactor. Inasmuch as certainimpurities, when present in uncontrolled amounts, can deleteriouslyaffect the activity of the catalyst of the present invention, it isimportant to take the necessary precautions to eliminate such impuritiesfrom the reactants. Such impurities include, for example, carbon dioxideand oxygen. The usual conventional purging methods are employed toeliminate these impurities, so that the reaction can take place withouttheir presence. Thus, the diluent is so treated, and the polymerizationreactor is purged with an inert gas.

When the polymerization is terminated, any one of many working-upprocedures can be employed to inactivate the catalyst and recover thefinal product. For example, in one process the polymer is recovered byentraining the same in diluent vapor. In another process, an inactivatoris added to the catalyst, and the polymer is precipitated. The polymeris then separated from the precipitate and the diluent by anyappropriate step, such as decantation or filtration. On the other hand,it is often preferred to add only that amount of inactivator which caninactivate the catalyst without .[.simulaneously.]. .Iadd.simultaneously.Iaddend.precipitating the polymer, and in this way it is possible toadd to the polymer solution any one of various additives which areusually found in final polymer products.

As polymer additives, it is advantageous to add an anti-oxidant, such asβ-phenyl-naphthylamine or para-tert.-butyl cresol. After the addition ofsuch an antioxidant to the catalyst solution, the polymer can beprecipitated by the addition of a precipitant, such as ethyl .[.os.]..Iadd.or .Iaddend.isopropyl alcohol. In this connection, it is oftenadvantageous to add to the alcohol a complexing or chelating agent whichcan extract the metal of the catalyst from the polymer, thereby leavingthe metal in solution after the polymer is precipitated. Such complexingor chelating agents include acetylacetone and the disodium salt ofethylenediaminetetracetic acid.

It is further to be understood that other methods can be employed torecover the polymer from the reaction solution. After the polymer isseparated from the alcohol and diluent by filtration or any otherconventional separating process, the polymer is thereupon dried.

The finally obtained polymers produced by the present invention aregenerally normally solid, but at the same time, by manipulation of thereaction times, temperatures, and quantities of catalyst, it is possibleto obtain polymers which range from lower molecular weight liquids tovery high molecular weight solids.

With respect to the polybutadienes which are obtained by this invention,the microstructure thereof has been determined by infrared spectroscopyaccording to the method of D. Morero, A. Santambrogio, L. Porri, and F.Ciampelli ("La Chimica et l'Industria" [Chemistry and Industry], XLI, 8,1959).

The structure of the polymers obtained by this invention can also bevaried by the selection of specific species of components (a) and (b),and/or varying the relative proportions thereof. For example, by theutilization of trifluoroacetic acid as component (b), the resultantcatalyst directs the polymerization stereospecifically to the productionof polymers having a very high cis-1,4-content, as compared for example,to polymers obtained by the use of other halogenated organic acids. Withrespect to chlorinated inorganic acids, it is to be noted thehydrochloric acid yields polymers which are essentially cis-1,4, whereasthe use of hydriodic acid leads to polymers which are essentiallytrans-1,4.

In summation, this invention not only is advantageous because component(b) is a readily available, inexpensive, easily handleable substance,but also the catalyst as a whole can be tailor-made to the production ofpolymers having the desired geometrical configurations, with theconcomitant properties associated therewith.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the specification and claims in any way whatsoever.

EXAMPLE 1A

Under an inert atmosphere, there are mixed 8 cc. of butadiene- 1,3 inthe liquid phase, 6 cc. of a solution of 0.12 mol per liter ofbis-(cyclooctadiene) nickel of the formula (C₈ H₁₂)₂ Ni(o) in toluene,and 1 cc. of a toluenic solution of 0.27 mol per liter of anhydroushydrochloric acid. The molar ratio of the nickel compound to thehydrochloric acid is 2.6. The reaction mixture is then agitated for 20hours at 55° C.

The resultant reaction mixture is treated with aqueous methyl alcoholcontaining an anti-oxidant, for example, N-phenyl-β-naphthylamine, and acomplexing agent for nickel, for example, acetylacetone. Theprecipitated polymer is purified by dissolving the same in benzene,followed by filtration and re-precipitation by methyl alcohol. There isthus obtained an elastomeric polybuadiene containing 84% cis-1,4-units,13% trans-1,4-units, and 3% vinyl units, the conversion from the monomerinto the polymer being 20%.

EXAMPLE 1B

For purposes of comparison, Example 1A is repeated without utilizingcomponent (b), the hydrochloric acid. In this case, there is obtained,other than the oligomers, some polybutadiene powder containing more than85% trans-1,4-units. The over-all yield with respect to polybutadiene isonly about 1.5%.

EXAMPLE 1C

For purposes of comparison, Example 1A is repeated, but this time,without employing component (a), the bis-(cyclooctadiene) nickel. Inthis case, there is no observed formation of any polymer.

EXAMPLE 2

Under an inert atmosphere, there are added 6 cc. of a solution of 0.1mol per liter of bis(cyclooctadiene) nickel(o) to a solution of 8 cc. ofbutadiene in 10 cc. of toluene. 5 cc. of a solution of 0.1 mol per literof anhydrous sulfuric acid are added to the reaction mixture. The molarratio of the nickel complex to the sulfuric acid is 1.2.

The reaction mixture is agitated at 55° C. for 20 hours, therebyobtaining a 60% conversion into polybutadiene having an intrinsicviscosity of about 0.7. The finally obtained polymer is 80% cis-1,4, 18%trans-1,4, the remainder being vinyl bonds.

EXAMPLE 3

Example 2 is repeated, except for a reduction in the quantity ofsulfuric acid from 5 cc. to 1 cc., thereby increasing the molar ratio of1.2 to 6.1. In this case, a polymer is obtained with a conversion of31%, the resultant polymer being 31% cis-1,4, 65% trans-1,4, and 4%vinyl bonds.

EXAMPLE 4

To a solution of 8 cc. butadiene in 7 cc. of toluene, there are added 6cc. of a solution of 0.11 mol per liter of bis-(cyclooctadiene)nickel(o) in toluene and 3 cc. of a solution of 0.1 mol per liter ofpicric acid in toluene. By operating under the same experimentalconditions as described in the preceding examples, there is thusobtained about 3% of polybutadiene containing more than 90%cis-1,4-units.

EXAMPLE 5

There are added 6 cc. of a solution of 0.11 mol per liter ofbis-(cyclooctadiene) nickel to a solution of 8 cc. of butadiene in 9 cc.of toluene. To this mixture, there are added 6 cc. of a solution of 0.1mol per liter of trichloroacetic acid in toluene which results in amolar ratio of the complex to the acid of 1.1. After agitating thisreaction mixture at 55° C. for 20 hours, there is thus obtained, at aconversion of 36%, polybutadiene containing 90% cis-1,4-units, 8%trans-1,4-units, the remainder being vinyl bonds.

EXAMPLE 6

Example 5 is repeated, except that trichloracetic acid is replaced bytrifluoroacetic acid, all other things being equal. The conversion isincreased to 70%, the microstructure remaining predominantly cis-1,4.

EXAMPLE 7

To a solution of 8 cc. of butadiene in 9 cc. of toluene, there are added6 cc. of a solution of 0.1 mol per liter of bis-(cyclooctadiene) nickeland 5 cc. of a solution of 0.1 mol per liter of paratoluenesulfonicacid. After the reaction mixture is agitated for 20 hours at 55° C.there is thus obtained a 37% conversion of a polymer having an intrinsicviscosity of about 0.2., the microstructure of which is essentiallyabout 50% 1,4-cis and 50% 1,4-trans.

EXAMPLES 8 to 16

The same operating conditions employed in Example 1 are used. In eachinstance, a polymerizable monomer, bis-(cyclooctadiene) nickel(o), ananhydrous acid, and an organic solvent are agitated at 55° C. Thepolymer is recovered as indicated in Example 1, and its intrinsicviscosity η is measured at 30° C. in benzene. The specific operatingconditions and results are found in the following Table I.

                                      TABLE I                                     __________________________________________________________________________                                 Ni  Acid                                                                              Reaction                                                                           Conver-                                                                            Microstructure,                                                                           [η]                                         Milli-                                                                            milli-                                                                            time,                                                                              sion,                                                                              Cis                                                                             Trans     30° C.      Ex.                                                                              Acid    Solvent   Monomer mols                                                                              mols                                                                              hours                                                                              percent                                                                            1,4                                                                             1,4   Vinyl                                                                             C.sub.8            __________________________________________________________________________                                                               H.sub.6            8  Trichloroacetic                                                                       20 cc. toluene                                                                          5.2 g. butadiene                                                                      1   1   15   27.2 80.7                                                                              16.6                                                                              2.7 0.24               9  Hydriodic                                                                             16 cc. cyclohexane                                                                      5 g. butadiene                                                                        0.66                                                                              0.6 20   64.5 0   .sup.1 100                                                                        0                                 +toluene.                                                          10 "       "         "       0.66                                                                              1.2 20   57.4 0   .sup.1 100                                                                        0                      11 "       "         "       0.66                                                                              0.15                                                                              20   49.9 0   .sup.1 100                                                                        0                      12 "       19 cc. cyclohexane                                                                      5.2 g. butadiene                                                                      0.96                                                                              0.96                                                                               6   30.4 0   .sup.1 100                                                                        0                                 toluene.                                                           13 Trichloroacetic                                                                       10 cc. toluene                                                                          3.4 g. isoprene                                                                       0.5 1   48   22.5 35  .sup.2 55                                                                         10                     14 "       "         "       0.5 0.5 48   6.3  35  .sup.2 55                                                                         10                     15 "       "         "       0.5 0.5 48   5.7  35  .sup.2 55                                                                         10                     16 "       "         5 g. styrene                                                                          0.5 0.5 48   8.5                                 __________________________________________________________________________     .sup.1 The infrared spectrum indicates two absorptions at 770 and 1050        cm.sup.-1, characteristic of crystallinity. This observation, moreover,       has been confirmed by X-ray crystallography.                                  .sup.2 The percentages of 1,4-units were estimated by nuclear magnetic        resonance. However, these analyses indicate a 10% deficiency in ethylenic     protons. The percentages of the vinyl bonds were determined by infrared       spectrometry.                                                            

EXAMPLES 17 to 29

These examples illustrate the preferred embodiment of this inventionwherein the complex of the transition metal, component (a), is subjectedto a pretreatment. Under an inert atmosphere, there are mixed 8 cc. ofbutadiene-1,3 in the liquid phase, that is 5.2 g., with 2.2 g. ofbis-(cyclooctadiene) nickel of the formula (C₈ H₁₂)₂ Ni and 20 cc. ofheptane. This mixture is agitated at 20° C. for about 1 hour. Afterevaporation under vacuum (0.2 mm. Hg) at 20° C. for 1 hour, there isthus obtained a red oil which is then taken up in a solution of heptane.The resultant solution is titrated to determine the concentration ofnickel, and it is found to have 3.9 g. of nickel per liter. To 6 cc. ofthis solution, there are added 8 cc. of liquid butadiene-1,3, and thenthe remainder of the solvent and anhydrous acid.

The polymerization commences and is continued at 55° C. under agitation.(Example 27 is conducted at a polymerization temperature of 25° C.) Thereaction time is varied according to the following Table II. The polymeris then worked up and recovered as in Example 1.

The specific operating conditions and results of the process are setforth in the following Table II.

                                      TABLE II                                    __________________________________________________________________________                                      Reaction                                                                            Conver-                                                                            Microstructure, percent                                  Ni,  Acid,                                                                              time, sion,                                                                              Cis Trans   [η] 30.degree                                                             . C.                 Example                                                                             Acid     Solvent  millimols                                                                          millimols                                                                          hours percent                                                                            1,4 1,4 Vinyl                                                                             C.sub.6 H            __________________________________________________________________________    17    Trichloroacetic                                                                        20 cc. heptane                                                                         0.4  0.4  3     26   90.5                                                                              6.6 2.9 0.69                 18    "        "        0.4  0.8  3     8.4  90.9                                                                              6   3.1                      19    "        "        0.4  1.6  3     0.3  83  12.2                                                                              4.8                      20    "        "        0.4  0.2  3     3.3  79.5                                                                              18  2.5                       20A  Without acid                                                                           "        0.4       3     0                                     21    Trifluoroacetic                                                                        "        0.4  0.4  3     89.5 90.8                                                                              4.5 4.7 0.57                 22    Picric   20 cc. heptane+                                                                        0.4  0.4  3     8.3  87  9.6 3.4 0.82                                toluene.                                                       23    "        "        0.4   0.53                                                                              3     14.2 92.5                                                                              4.6 2.9 0.545                24    "        "        0.4  0.8  3     46.4 92.6                                                                              4.7 2.7                      25    Methanesulfonic                                                                        20 cc. heptane                                                                         0.4  0.4  15    32.7 43.5                                                                              51.2                                                                              5.3                      26    "        "        0.4  1.6  15    16.4 51  44.2                                                                              4.8                      27    "        "        0.4  1.6  17    22.3 40.8                                                                              57.9                                                                              1.3                      28    Hydrochloric                                                                           "        0.4  0.8  3     12.7 83.8                                                                              13.3                                                                              2.9 0.24                 29    Trichloroacetic                                                                        20 cc. CH.sub.2 Cl.sub.2                                                               0.4  0.4  3     11.5 55.3                                                                              43  1.7 0.23                 __________________________________________________________________________

EXAMPLE 30

Using the same reaction conditions as in Examples 17 to 29, there isadded as the cocatalyst (b) a mixture of trichloroacetic acid and tintetrachloride, so as to have a resultant molar ratio ofnickel:trichloroacetic acid of about 1. After a reaction time of 30minutes, there is obtained a 33% conversion into polybutadiene whencomponent (b) has a molar ratio of trichloroacetic acid to tintetrachloride of about 1; and correspondingly, a conversion of 25.4%when the molar ratio is 2.

The microstructure of the resultant polybutadiene is 86% cis-1,4, 12%trans-1,4, and 2% vinyl.

EXAMPLE 31

Using the same reaction conditions as Example 28, there is reacted atambient temperature hydrochloric acid with the reaction product ofbis-(cyclooctadiene) nickel with butadiene. The excess acid is liberatedby evaporation under vacuum. To the resultant evaporated residue thereis added the quantity of butadiene necessary for polymerization.

Under these conditions, there is obtained with a conversion rate of13.5%, comparable to that of Example 28, polybutadiene having amicrostructure of 90.5% cis-1,4, 7.7% trans-1,4, and 1.8% vinyl. Theintrinsic viscosity of the polymer is 0.83.

EXAMPLE 32

Under an inert atmosphere, there is mixed 4 cc. of butadiene with 2.9cc. of a solution of cyclododecatriene nickel in heptane (0.25 millimolof nickel complex), 10.6 cc. of heptane, and 0.94 cc. of a solution of0.534 mol per liter of trichloroacetic acid in heptane. After a reactiontime of 11/2 hours at 45° C. under agitation, there is obtained 1.36 g.of polybutadiene (conversion: 52.3%) having a microstructure of 93.2%cis-1,4, 3.8% trans-1,4, and 3% vinyl. The intrinsic viscosity of thepolymer is 0.57 as measured in benzene at 30° C.

The preceding examples can be repeated with similar success bysubstituting the generically and specifically described reactants andoperating conditions of this invention for those used in the precedingexamples.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions. Consequently, such changes and modifications are properly,equitably, and intended to be, within the full range of equivalence ofthe following claims.

What is claimed is:
 1. A catalyst composition consisting essentially ofthe reaction product of(a) a non-ionic coordination complex of atransition metal of Groups IV through VIII of Mendeleev's Periodic Tableas the nuclear atom, and unsaturated hydrocarbon as ligand, saidhydrocarbon having at least one pair of π electrons; and (b) a Bronstedacid, the molar of (a) to (b) being 0.1:1 to 3:1 respectively.
 2. Acatalyst composition as defined by claim 1 wherein said unsaturatedhydrocarbon is a cyclopolyolefin having about 5-1 carbon atoms permolecule, a nucleus of about 5-14 carbon atoms and about 2-6 doublebonds per molecule.
 3. A catalyst composition as defined by claim 2wherein the coordination compound is bis-(1,5-cyclooctadiene) nickel. 4.A catalyst composition as defined by claim 1 wherein the Bronsted acidhas a dissociation constant higher than 10⁻⁴.
 5. A catalyst compositionas defined by claim 1 wherein the Bronsted acid is trifluoroacetic acid.6. A catalyst composition as defined by claim 1 wherein the Bronstedacid is hydrochloric acid.
 7. A catalyst composition as defined by claim1 wherein the Bronsted acid is hydriodic acid.
 8. A catalyst compositionas defined by claim 1, further comprising a Lewis acid.
 9. A catalystcomposition as defined by claim 1 wherein the coordination compound issubjected to a pretreatment comprising reacting said coordinationcompound with a polymerizable monomer, the resultant reaction productbeing then reacted with the Bronsted acid.
 10. A catalyst composition asdefined by claim 9 wherein said polymerizable monomer is butadiene. 11.A catalyst composition as defined by claim 9 wherein at least a portionof hydrocarbon ligand of the coordination compound is separated bydistillation after the reaction of the coordination compound with thepolymerizable monomer.
 12. A catalyst composition as defined by claim 9wherein at least 0.5 mol of polymerizable monomer is employed per atomof transition metal in the form of the coordination compound.
 13. Acatalyst composition as defined by claim 9 wherein the addition of saidreaction product to the Bronsted acid is conducted in the absence ofunreacted polymerizable monomer, and excess Bronsted acid is separatedfrom the resultant product.
 14. A process for the polymerization of aconjugated diolefinic hydrocarbon, which process comprises polymerizingsaid hydrocarbon is a substantially anhydrous medium and in the presenceof a catalyst composition as defined by claim
 20. 15. A process for thepolymerization of a conjugated diolefinic hydrocarbon, which processcomprises polymerizing said hydrocarbon in a substantially anhydrousmedium and in the presence of a catalyst composition as defined by claim5.
 16. A process for the polymerization of a conjugated diolefinichydrocarbon, which process comprises polymerizing said hydrocarbon in asubstantially anhydrous medium and in the presence of a catalystcomposition as defined by claim
 13. 17. A process for the polymerizationof butadiene which process comprises polymerizing butadiene in theliquid phase in contact with a catalyst comprisingbis-(1,5-cyclooctadiene) nickel and an acid selected from the groupconsisting of trifluoroacetic acid, hydrochloric acid, and hydriodicacid, the molar ratio of the bis-(1,5-cyclooctadiene) nickel to the acidbeing 0.01:1 to 50:1, respectively.
 18. A catalyst composition asdefined by claim 1, wherein said transition metal is nickel.
 19. Acatalyst composition as defined by claim 18 wherein the Bronsted acid istrifluoroacetic acid.
 20. A catalyst composition according to claim 1,wherein said transition metal is from Groups V through VIII ofMendeleev's Periodic Table.
 21. A process for the polymerization of anethylenically unsaturated hydrocarbon, which process comprisespolymerizing said hydrocarbon in the presence of a catalyst compositionas defined by claim 18, in a substantially anhydrous medium.
 22. Aprocess for the polymerization of an ethylenically unsaturatedhydrocarbon, which process comprises polymerizing said hydrocarbon inthe presence of a catalyst composition as defined by claim 19, in asubstantially anhydrous medium. .Iadd.
 23. A process for producingpolybutadienes, said process comprising polymerizing butadiene-1,3 inthe presence of a catalyst which is a product obtained by reacting aπ-allylic complex of a transition metal of Groups IV through VIII of thePeriodic Table with a compound of the Formula III: ##STR1## wherein R₇,R₈ and R₉ are independently selected from the group consisting ofhydrogen, halogen; and alkyl, alkenyl, and haloalkyl groups having from1 to 6 carbon atoms; and Y is hydrogen. .Iaddend. .Iadd.
 24. A processaccording to claim 23, wherein the polymerization is carried out at atemperature ranging from -40 to +80° C. in a medium of an inert organicsolvent selected from the group consisting of aliphatic, cycloaliphatic,aromatic hydrocarbons and halogen derivatives thereof. .Iaddend..Iadd.25. A process according to claim 23, wherein said product is formed inthe presence of the butadiene-1,3 monomer. .Iaddend..Iadd.
 26. Abutadiene polymerization catalyst which is a product obtained byreacting a π-allylic complex of a transition metal of Groups IV- VIII ofthe Periodic Table with a compound selected from the Formula III:##STR2## wherein R⁷, R⁸ and R⁹ are independently selected from the groupconsisting of hydrogen, halogen; and alkyl, alkenyl, and haloalkylgroups having from 1 to 6 carbon atoms; and Y is hydrogen. .Iaddend..Iadd.
 27. A process for producing polybutadiene, said processcomprising polymerizing butadiene-1,3 in the presence of a catalystwhich is a product obtained by reacting:(a) a non-ionic coordinationcomplex of a transition metal of Groups IV through VIII of Mendeleev'sPeriodic Table as the nuclear atom, and unsaturated hydrocarbon asligand, said hydrocarbon having at least one pair of π electrons; and(b) a carboxylic acid. .Iaddend. .Iadd.
 28. A process as defined byclaim 27 wherein said carboxylic acid is selected from the groupconsisting of acetic acid, formic acid, isobuteric acid,monochloroacetic acid, dichloroacetic acid, trichloroacetic acid andtrifluoroacetic acid. .Iaddend..Iadd.
 29. A process as defined by claim27 wherein said non-ionic coordination complex is bis π-allyl nickel..Iaddend..Iadd.
 30. A process as defined by claim 28 wherein saidnon-ionic coordination complex is bis π-allyl nickel. .Iaddend. .Iadd.31. A process according to claim 23, wherein the π-allylic complex isselected from the group consisting of bis-(π-allyl) nickel,π-allyl-cyclopentadienyl nickel and tris-(π-allyl) chromium.